1. Field of the Invention
The present invention generally relates to apparatuses and methods for managing the state of an external apparatus, and more particularly to an apparatus and method for managing the state of an apparatus which apparatus and method realizes a managed object (MO), which is a function of managing the state of an apparatus, by an application and retains the state of the external apparatus in a database.
2. Description of the Related Art
Conventionally, a managed object (MO), which is a function of managing the state of an apparatus has been realized by a general application and information required to be retained inside a computer such as a workstation (WS) or a personal computer (PC) has been retained by using a database. According to this conventional method, a user is required to perform control or obtain information by using the application managing the MO and protocols such as the common management information protocol (CMIP) or the simple network management protocol (SNMP).
On the other hand, in the case of managing or controlling the state of a communication device or a computer, information not directly related to the managed apparatus, such as user information, is also required in addition to simple management of the apparatus, thus making a database retaining such user information essential.
FIG. 1 is a block diagram showing a network management system employing the conventional method. In FIG. 1, a network management system (NMS) 10 is composed of a user application 11 such as a graphical user interface (GUI) and a computer 12 such as a WS or a PC, and manages apparatuses to be managed (managed apparatuses) 13 such as transmission apparatuses. For convenience of description, only one of the managed apparatuses 13 will be referred to in the following description.
In order to handle information on the managed apparatus 13, it is necessary to retain the information as an MO 15 in the computer 12 by using databases (DBs) 16 and 17 for retaining the information inside the MO 15. The necessity of retaining the information is as follows:
First, if the information set in the managed apparatus 13 is retained only thereby without being retained by the NMS 10, it is difficult to restore the managed apparatus 13 to its original state when the information retained by the managed apparatus is lost.
Secondly, if a method is employed by which method the information set in the managed apparatus 13 is obtained therefrom every time the NMS 10 reads out the information, the NMS 10 takes time in performing control and reading due to an interface protocol with the managed apparatus 13. Since time required in reading out the set information can be reduced by the NMS 10 retaining the set information, the set information is retained in the database 16 as shown in FIG. 2.
Thirdly, if the managed apparatus 13 can asynchronously notify the NMS 10 of information on an internal change of the managed apparatus 13, such as failure information, switching information of a redundant configuration part, and an operating state, the NMS 10 can always check the state of the managed apparatus 13 without obtaining the information therefrom by retaining the event in the NMS 10 as shown in FIG. 3. Thereby, processing time can be reduced.
For the above-described reasons, an application for monitoring and controlling the managed apparatus 13 defines the MO 15 by modeling and retains a variety of information in the NMS 10 by using the database 16.
However, the NMS 10 does not only handles information transmitted by way of the MO 15. As is often the case, the NMS 10 directly handles information retained in the database 17, for instance, general information such as a place where the managed apparatus 13 is provided. Therefore, the user application 11 is required to use two interfaces with the computer 12; one by way of the MO 15 and the other directly with the database 17.
According to the conventional method and system, generally, a database is used to retain and manage information handled by a user application. However, a normal database only manages information stored by a user, and is prevented from managing actual information on a managed apparatus unless the user stores the information. The information may not represent the actual state of the managed apparatus depending on timing at which the user stores the information. That is, the interface of the database cannot process the actual information on the managed apparatus unless the information is once stored in the database.
Further, in order to manage the state of a communication device or a computer, it is necessary to read out the actual state of the apparatus or set a variety of control information in the actual apparatus. In order to realize such a function, an application shall be installed as an MO. This requires the user application to use a protocol different from an interface with the database (an access by a structured query language (SQL) statement), such as the SNMP or the CMIP. As a result, the user application is required to have many access interfaces installed therein. That is, an interface for accessing the actual apparatus such as the managed apparatus is required in addition to the access interface to the database, thus increasing costs.
Further, in the case of realizing a large-scale system, generally, the system is formed by providing a server including the MO and a server including the database separately from each other for processing load sharing. However, according to this method, the server including the database is accessed via the server including the MO from the user application in order to obtain the actual information on the managed apparatus, thus requiring processing time longer than that required in directly accessing the database. In a system where real-time processing is required, such as a system for monitoring and controlling a managed communication device, it is necessary to reduce processing time. Therefore, a delay in processing causes a problem.
Further, in the case where the MO and the database is provided separately, in order to realize transaction processing performing, for instance, exclusive access control of information, a locking operation, cancellation of an operation, and recovery, a transaction function is required to be installed separately in the MO-side application, though the transaction function of the database is also available. This increases the cost of creating the application.